Bloodwork inaccuracies?

Gigi
Hi ladies, 
I need to ask your advice. In May, my family doctor told me to go for blood tests to check FSH, LH levels. He never gave me any advice that it needed to be done on the third day of my cycle. No one at the lab told me this either. 
The test came back normal, but I'm wondering if this could be inaccurate because it was done at the wrong time? I have posted before of my suspicions that thus doctor was not giving us the right advice; I'm so upset that he did not tell me that the test needs to be done on the third day. 
What do you think ladies?